(BGM from "Angels")
Angels, pronounced as "Shito"(means "Disciple" in English) in Japanese, are mysterious entities first came up 15 years ago just before "Second Impact" happened. The Third Angel suddenly strikes Tokyo-3 after 15 years. They can create "Absolute Terror Field" which make it impossible for normal weapons to damage them. They come into different forms and they always attack solitarily. Their real aim of coming is still unknown.
(According to the Old Testament of the Bible , Angels are the servants of God. It also represents the 12 disciples of Christ in the New Testament.)
Fifth Angel, Ramiel
More in-depth info about Angels can be found below. Be warned that the following info is EXTREMELY SPOILING and is suitable ONLY for those who have watched TV episodes 1-24(at least). If you do not follow I'm sure you will regret what you have done.
Warning! You are now on the way down to Terminal Dogma under Nerv headquarters! Return before it is too late!
You are now near Terminal Dogma! Return now! This is your last warning!
It's already too late...you have come to Terminal Dogma. May God bless you.
Angels are beings that resemble humans very much(99+% genetic similarity with the humans) and possess a variety of forms. Actually human is considered as the 18th Angel. Their names were given according to the Angels' names from "Dead Sea Scrolls". In 2000, the second Angel(the glowing giant in "Second Impact") named "Adam" was discovered in Antarctic by some scientists. They attempted reducing it to its embryo form, and the tremendous energy released caused "Second Impact". Angels only objectives are to find and become one with Adam(that's why Adam was shrunk - to keep his powers at a minimum to keep damages low when more Angels were prophecied to come in search of him). Their appearing is also a major hindrance for mankind to evolve to a higher state of existence(the ultimate aim of "Human Completion Project"), something forbidden by God.
So you may ask, if Adam is the second Angel, what is the first Angel then? Well, the fact is that although Adam was the FIRST Angel created in God's image, he was only the SECOND Angel found by mankind. The FIRST FOUND Angel is Lillith. More info about Lillith can be found here.
(Based on the Old Testament of the Christian Bible, Adam was the first man to have been created by God in his own image.)
Note: Feel free to tell me if you find anything wrong in the above info.
Neon Genesis Evangelion and related images are copyrighted by GAINAX/ Project EVA, TVX, NAS.